Shield for a latch bolt



July 11, 1967 A. E. FLOYD SHIELD FOR A LATCH BOLT 2 Sheets-Sheet 1 Filed Aug 26, 1965 ammo a ALF/e50 E. FLOYD 1 M M fiacwezz ATTOR N EY July 11, 1967 A. E. FLOYD SHIELD FOR A LATCH-BOLT 2 Sheets-Sheet 2 Filed Aug. 26,. 1965 ALFRED E. FLOYD lfi w/ ATTOR N EY United States Patent 3,330,587 SHIELD FOR A LATCH BOLT Alfred E. Floyd, Guilford, Conn, assignor to Sargent &

Company, New Haven, Conn., a Connecticut corporation Filed Aug. 26, 1965, Ser. No. 482,853 Claims. (Cl. 292-346) This invention relates to a shield for a latch bolt which 'manner as to engage the opposing beveled face of the bolt and force the bolt, which is usually only relatively lightly spring biased to the extended position thereof, to its retracted position. The shield of the present invention effectively inhibits such a probe from following the opposing beveled face of the bolt in a manner to cam the bolt inwardly.

Accordingly, one object of the invention is to provide a latch construction incorporating a bolt shield. Another object is to provide a shield which is movably mounted for retraction by the bolt upon authorized operation of the latch to clear the strike with which the bolt cooperates. Another object is to provide in a latch construction a bolt shield of simple manufacture which is easy and inexpensive to incorporate in such a construction. Further objects of the invention will be apparent from the following detailed description of one of the presently preferred embodiments thereof.

In the drawings:

FIG. 1 is a top view, partially in section, illustrating a latch construction incorporating a shielded bolt embodying my invention, omitting the manually operable latch-operating member and illustrating the latch in association with a door and a door, frame equipped with a strike;

FIG. 2 is a sectional view on line 22 of FIG. 1;

FIG. 3 is a sectional view on line 33 of FIG. 1;

FIG. 4 is a sectional view on line 4-4 of FIG. 1;

FIG. 5 is a sectional view on line 55 of FIG. 4;

FIG. 6 is a view similar to FIG. 5 but illustrating the condition of the parts of the latch in the retracted position of the bolt; and

FIG. 7 is a view similar to FIG. 2 but illustrating the condition of the parts when the bolt is in the retracted position.

In the drawings, the latch assembly is indicated generally at 10 and the strike with which it cooperates at 11. In the illustrated form, the strike is recessed in the door frame 12, as shown in FIG. 1, and a door stop is provided as at 13. The door is indicated at 14 and, as indicated in the last-mentioned view, the latch 10 is of the rim type and applied to the inner face 15 of the door, the outer face of the door being indicated at 16. The illustrated latch construction is of the general type commonly employed to latch exit and fire doors and equipped with panic hardware. As shown in FIG. 3, the latch is provided with an operating arm 17 which is swingable by means of the usual cross bar, not shown, having an end received in the opening 18 in the arm.

The cover of the latch is indicated at 19 and is provided with suitable openings for the arm 17, the bolt, indicated generally at 20', and fasteners 21 for attaching the cover to the support or chassis of the latch indicated generally at 22. Other openings may be provided in the cover if desired. The chassis is provided with suitable openings 3,330,587 Patented July 11, 1967 (one being shown and indicated at 23) for the reception of the fasteners to secure the chassis to the inner face 15 of the door.

The arm 17 is swingably mounted on a pivot 24 extending through side walls of the chassis and through a portion of the arm disposed intermediate the last-mentioned walls, and the arm is biased to the position shown in FIGS. 3 and 5 by a compression spring 25 reacting against the chassis and a spring follower 26 also pivoted on the pin 24 in straddling relation to a portion of the arm and engageable with the arm 17, the spring follower having a boss 27 supporting one end of the spring 25, the other end of the spring 25 being supported in like manner, not shown, from the chassis.

A slide 28, operating the bolt 20 in a manner which will be apparent hereinafter on actuation of the arm 17, is pivoted to the latter in a conventional manner at a point eccentric to the pivot 24, the slide being located between the side walls of the chassis and arranged vertically. The aforementioned construction and operation of the spring- 'biase-d arm 17 and the slide 28 is conventional and need not be described in further detail with reference to the invention.

The bolt 20, pivoted at 29 to one side wall of the chassis 22, is swingable on a horizontal axis and is provided with a tapered surface 30 which, when engaged with the strike 11 as the door is closed, is cammed by the strike in a direction to retract the bolt suffi-ciently to wipe past a portion of the strike 11 until the door reaches the closed position shown in FIG. 1. As shown in the last-mentioned view, the bolt 20 is in its extended position entering a recess formed by the strike, this being the latched position of the bolt.

The bolt is urged to this position by a tension spring 32 having one end thereof secured, as at 33, to the chassis and having the other end thereof secured to a pin 34 protruding from the bolt within the chassis and arranged eccentrically with respect to'the pivot 29, as shown in FIGS. 4 and 5. The bolt is provided with ears 36 between which the slide 28 is guided, the ears receiving the pin 34. The slide 28 is provided with a projection 38 extending under and engageable with the pin 34 in such manner that, when the slide 28 is raised from the position of FIG. 4 to the position of FIG. 6 by downward swinging movement of the arm 17, the bolt is swung on its pivot in a direction to be retracted to clear the strike. It will be understood that when the door is closed in the previously-described manner, the bolt swings inwardly, with the pin 34 swinging upwardly and away from the projection 38 on the slide.

For the purpose of obtaining clearance with the strike .11, the bolt is provided with tapered surfaces 40 and 41.

The strike is shown recessed in the door frame. It may be secured to the door frame as by screws 42. It will be understood from the foregoing that outward movement of the bolt 20 is limited by engagement of the pin 34 with the projection 38 of the slide. The movement of the arm 17 influenced by the spring 25 is limited by a suitable abutment, not shown, on the latter engageable with a portion of the chassis.

The bolt face generally opposite the face 30 is partially cut away, providing a groove 44 (FIG. 3) extending through the beveled bolt surface 40. This cut-away portion of the bolt accommodates in flush relation 2. bolt shield, indicated generally at 46, in the form of a lever having integrally formed arm portions 47, 48, the former being pivoted at its distal end to the chassis at a point remote from the pivot 29 by a pin 49. The shield-forming lever 46 is biased in a counterclockwise direction as The lever arm 48 terminates at its distal end in a finger 50 which, when the shield is in the position shown in FIG. 2, projects beyond the surface 40 of the bolt under the influence of the spring 45. The aforementioned cut-away portion of the bolt provides clearance for the finger 50 during swinging movement of the lever 46 relatively to the bolt, and provides a shoulder portion 51 forming a cam surface for cooperation with a cam follower surface 52 provided on a tail 53 of the shield-forming lever 46.

A surface 55 of the finger 50 projects beyond the bolt surface 40 when the bolt is in the extended position shown in FIG. 2, this finger surface being an upper surface, as shown in the last-mentioned view, and being slanted or angularly arranged (see FIG. 2) with reference to the axis of the pivot 49 of the shield so that when a thrust is exerted against this surface by a probe such as a card inserted between the door and the door frame, there is no tendency for the shield to be swung in a retracting direction or in a clockwise direction as viewed in FIG. 2. It should be noted that the finger surface 55 is at approximately right angles to the beveled surface 40 of the bolt.

As shown in the last-mentioned view, the finger 50 may extend a substantial depth into the srike 11, and there is no tendency for a probe to ride over the finger 50 as the surface 55 thereof is substantially flat, as shown in FIG. 2, merging with a surface formed on a radius and of convex contour. Thus a probe inserted in the aforementioned manner may not follow the beveled surface 40 of the bolt sufficiently to cam the bolt to a retracted position to unlatch the bolt. The shield 46 serves as an abutment or stop for a probe.

The finger surface 55 which provides an abutment for a probe such as a card and which lies below the pivot 49 is formed in a plane converging with a perpendicular plane in which the axis of the pivot 49 lies, as indicated in FIG. 2, forming an acute angle of approximately 45 degrees. Hence a thrust on this surface of the shield cannot effect swinging movement of the shield to retract the latter.

It will be understood from the foregoing that retraction of the beveled bolt 20 from the strike through operation of the actuating arm 17 effects retraction of the shield 46 protecting the bolt. Upon retraction of the bolt and the shield from the position of FIG. 2 to the positions of FIG. 7 in the last-mentioned manner, the cam surface 51 of the bolt moves over the cam surface 52 of the shield. This camming action, as seen by a comparison of FIGS. 2 and 7, effects a greater amplitude of movement of the shield than the amplitude of swinging movement of the bolt 20 as aforesaid.

It is to be noted here that the cam follower surface 52 of the shield is disposed at a greater distance from the pivot 49 than the cam surface 51 of the bolt is from the pivot 29. In the retracted position of the shield 46 shown in FIG. 7, the shield is withdrawn to such an extent that the tip of the finger 50 is substantially flush or below the beveled surface 40 of the bolt. When the arm 17 is permitted to return to its normal position shown in FIGS. 3 and 5, the slide 28 of the latch travels downwardly in the case from the position shown in FIG. 6 under the influence of the spring 25, allowing both the spring-biased bolt 20 and the spring-biased shield 46 to once again assume the positions shown in FIG. 2. If desired, the latch may be provided in a conventional manner with a keyactuated rollback 58 cooperating with a projection 59 (see FIGS. and 6) on the slide 28 to operate the bolt to retract the latter. The spring-biased shield 46 is cammed inwardly by the spring-biased bolt 20 when the latter is cammed inwardly by the door step and strike. To effect this movement of the shield, the camming action 4 of the bolt 20 on the shield 46 is the same as that previously described with reference to the retraction of the shield on operation of the arm 17.

While only one form of the invention is shown in the drawings and described above, it will be readily apparent to those versed in the art that the invention may take other forms and is susceptible of various modifications in details without departing from the principles of the invention and the scope of the appended claims.

I claim:

1. In a latch construction for application to a swinging closure cooperating with means defining an opening for the closure and equipped with means providing a closure stop and strike, the door having a face for cooperation with the closure stop and adjacent and at right angles thereto an edge, the combination of a support for fixed application to the closure, a spring-biased latch bolt pivotally mounted on the support on an axis parallel to the door edge and normally projecting laterally from the closure, having a tapered surface with reference to said edge of the door to provide clearance with the strike when the bolt is retracted, the bolt having another surface tapered with reference to said face of the door, which on engagement with the means defining the stop and strike cams the bolt to a retracted position against the influence of said bias, bolt-operating means movably mounted on the support for retracting the bolt, a bolt shield for projecting normally beyond the first mentioned tapered surface of the bolt, to provide a stop for a probe inserted between the closure and the means defining the closure stop and strike for the purpose of camming the bolt to a retracted position, and means pivotally mounting the shield for movement independently of the bolt and on an axis parallel to the door edge, so that the shield may be retracted without movement of the bolt, said shield being spring-biased toward the aforementioned projecting position, and coacting means on the bolt and shield for retraction of the latter into the bolt and for movement therewith on retraction of the latter, either upon the bolt being cammed inwardly by engagement with the stop and strike, as on closing of the door, or upon actuation of said bolt-operating means.

2. A latch construction as defined in claim 1 wherein the portion of the shield projecting beyond the bolt is of finger-like outline and has an edge portion providing the probe stop which is substantially planar lying in a plane substantially at right angles to the first mentioned tape-red surface of the bolt.

3. A latch construction as defined in claim 1 wherein the swinging axes of the bolt and shield are in eccentric relationship and spaced from one another.

4. A latch construction as defined in claim 3 wherein there is provided a spring between the support and said shield urging the latter toward its projected position.

5. A latch construction as defined in claim 4 wherein said shield is recessed in said bolt and wherein said coacting means on the bolt and the shield comprises a cam portion on the bolt and a cam follower portion on the shield.

References Cited UNITED STATES PATENTS 464,478 12/1891 Matthews 292223 X 559,960 5/1896 Witt 70-4l8 1,993,659 8/1935 Goodman et al. 292ll 2,107,300 2/1938 Kilpatrick .a 70-418 X 2,534,693 12/1950 Adams.

MARVIN A. CHAMPION, Primary Examiner.

EDWARD C. ALLEN, Examiner.

J. R. MOSES, Assistant Examiner. 

1. IN A LATCH CONSTRUCTION FOR APPLICATION TO A SWINGING CLOSURE COOPERATING WITH MEANS DEFINING AN OPENING FOR THE CLOSURE AND EQUIPPED WITH MEANS PROVIDING A CLOSURE STOP AND STRIKE, THE DOOR HAVING A FACE FOR COOPERATION WITH THE CLOSURE STOP AND ADJACENT AND AT RIGHT ANGLES THERETO AN EDGE, THE COMBINATION OF A SUPPORT FOR FIXED APPLICATION TO THE CLOSURE, A SPRING-BIASED LATCH BOLT PIVOTALLY MOUNTED ON THE SUPPORT ON AN AXIS PARALLEL TO THE DOOR EDGE AND NORMALLY PROJECTING LATERALLY FROM THE CLOSURE, HAVING A TAPERED SURFACE WITH REFERENCE TO SAID EDGE OF THE DOOR TO PROVIDE CLEARANCE WITH THE STRIKE WHEN THE BOLT IS RETRACTED, THE BOLT HAVING ANOTHER SURFACE TAPERED WITH REFERENCE TO SAID FACE OF THE DOOR, WHICH ON ENGAGEMENT WITH THE MEANS DEFINING THE STOP AND STRIKE CAMS THE BOLT TO A RETRACTED POSITION AGAINST THE INFLUENCE OF SAID BIAS, BOLT-OPERATING MEANS MOVABLY MOUNTED ON THE SUPPORT FOR RETRACTING THE BOLT, A BOLT SHIELD FOR PROJECTING NORMALLY BEYOND THE FIRST MENTIONED TAPERED SURFACE OF THE BOLT, TO PROVIDE A STOP FOR A PROBE INSERTED BETWEEN THE CLOSURE AND THE MEANS DEFINING THE CLOSURE STOP AND STRIKE FOR THE PURPOSE OF CAMMING THE BOLT TO A RETRACTED POSITION, AND MEANS PIVOTALLY MOUNTING THE SHIELD FOR MOVEMENT INDEPENDENTLY OF THE BOLT AND ON AN AXIS PARALLEL TO THE DOOR EDGE, SO THAT THE SHIELD MAY BE RETRACTED WITHOUT MOVEMENT OF THE BOLT, SAID SHIELD BEING SPRING-BIASED TOWARD THE AFOREMENTIONED PROJECTING POSITION, AND COACTING MEANS ON THE BOLT AND SHIELD FOR RETRACTION OF THE LATTER INTO THE BOLT AND FOR MOVEMENT THEREWITH ON RETRACTION OF THE LATTER, EITHER UPON THE BOLT BEING CAMMED INWARDLY BY ENGAGEMENT WITH THE STOP AND STRIKE, AS ON CLOSING OF THE DOOR, OR UPON ACTUATION OF SAID BOLT-OPERATING MEANS. 